Mold



Dec. 26, 1944. H. c. WINKEL MOLD Original Filed Aug. 28, 1940 2 Sheets-Sheet 1 Dec. 26, 1944. H. c. WINKEL MOLD Original Filed Aug. 28, 1940 2 Sheets-Sheet 2 i 1% w EE EEEEE N mmmmmmmnmmmmmmmmmnmmmmml @magnum mmmmmmmmmmmmmmmmmm vk m ,i .mu

QN Q Mx QN Patented Dec. 26, 1944 Original application August 28, 1940, Serial No. 354,495. Divided and this application March 2,

` 1942, Serial No. 132,993k

's claims.v (o1. 22153) This invention relates to molds and more par-` ticularly lto molds for casting grids for electric battery plates.- `It is especially adapted for use in connection with automatic grid molding machines such, for instance, as disclosed and claimed in my copending application Serial No. 354,495, of which this instant application'is a division.

It is an object of this invention to provide a grid mold having a new and novel arrangement and relationship of air compression chambers therein sov that the mold is completely lled during each molding operation and without the use of air vents. The mold may, therefore, be effectively used in continuously operated molding machines for high speed quantity production to produce substantially nless grids. The molds are constructed to equalize the pressures therein so that the back pressure of trapped gases is just sufiicient to counteract the pressure of the metal when all of the passages of themold are completely lled and without allowingthe passage of the molten material into the gas compression` spaces. The molds are, therefore, completely filled to form perfect strands in the finished grid and at the same time the grid may easily be removed, automatically or otherwise, from the molds. y v i n In casting grids for battery plates wherein the strands of the labyrinth-like plate areelongated and very small in diameter, it has been very diflicult to cause the molten metal'to completely fill the mold cavity and form perfect strands,

Furthermore, even if the grid is ejected from the mold, the air passages or vents soon becomefilled with metal, which prevents proper flow and results in imperfectly formed strands.

It has been found that, by the proper distribution of air compression chambers or grooves `machine. It is, therefore, an object Vto provide a require frequent cleaning. This is an important feature of this invention, as'it enables the use of` a simple high speed molding machine suitable for quantity production and with a minimum number of defective grids. l

Battery grids are cast in 'integral pairs, that is, two grids in a single casting with an outstanding terminal lug on each grid. The terminal lugs are oppositely disposed on the double grid and it has been found that, if these lugs 4can accurately `be cast without fins and with cleancut edges, they may be used as locating lugs in a trimming machine or other grid handling device, to which machine the grids may, if desired, be 'delivered directly from the molding simple and effectiveautomatic sealing means for sealing the mold adjacent the edges of the lug cavities whereby accurate clean-cut lugs Without fins are provided.

Another object is `to provide, particularly in a continuously moving'mold, means to enable the molten metal poured into the moving mold from a fixed pump orother suitable means to be properly distributed in the moving mold without being spilled therefrom.

`Other objects will be apparent from the speci- Iication and the appended claims.

In the drawings: Y

Fig.- 1 is a fragmentary face View of one of the mold sections and illustrates the mold cavity for forming the grid and the compression spaces for gas between the channels for forming the strands of the grid.

Fig. 2 is a diagrammatic side elevation of one of the double grids which may be molded by the mold construction shown in Fig. 1.

Fig. 3 is an enlarged horizontal detailed section through the closed mold after the metal has `been poured therein and is taken on a line subclosely associated with the strand cavities of the mold, air vents may be entirely dispensed with and a desired iiow of metal may be obtained so that perfect grids may be formed Without fins on the strands and without permitting any of the metal to enter the compression grooves. lBy this means the grids are perfectly formed and easily ejected from the molds and the molds do not i stantially corresponding to line3-`3 of Fig. 1.

Fig. 4 is an enlarged vertical section through the closedand lled'mold and' is taken on a line substantially correspondingto line 4-4 of Fig. 1. Fig'. 5 isa fragmentary face view of a slightly different type of mold particularly adapted for forming a grid withv so-called staggered strands and constructed to provide a corrugated bottom iin having ,considerably increased strength without increasing the thickness thereof so that the grid may more easily be handled without distorting the bottom iin.

Fig. 6 is an enlarged fragmentary sectional view through a closed and filled mold of the type shown in Fig. and is taken on a line substantially corresponding to line 6-6 of Fig. 5.

Fig. 7 is a vertical section through the bottom fin portion of the closed and lled mold and is taken on a line substantially corresponding to line 1 1 of Fig. 5.

Fig. 8 is a horizontal sectional view through the corrugated` bottonnnrportion of the closed' and".` lled mold and is taken on a line substantiallyv corresponding to line 8-8 of Fig. 5.

Fig. 9 is a face View of the upper portion of the?.

inner mold section.

Fig. 10 is an enlarged detail sectional View taken on line IU-IU of Fig. 9 and illustrates thezauto."A matic sealing means for casting clean-cutlocating lugs without ns. i

Fig. l1 is a perspective vieW ofthe sealing plug shown in Figs. 9 and 10.

It is extremely important for the successful operation of an. automatic, grid moldingmachine such, for instance, as disclosedlin my previously mentioned copending application that the molds should' be so constructed' that perfect grids' may be producedin such a .manner .that they matr easily be ejected therefrom. It hasbeen found.- that' this is best` accomplished without the use ofthe usual' vent holes or'air passages andby" the use of. compression chambers of" suilicientsize' and distribution with' respect to the strandcavities that the backpressure" of thegases is' just sufficientA to permit complete filling4 off the mold* without formingns onthestrands. The

drawingsillustratermolds suitable-forthis purpose'-f wherein -both sections of the mold are substan-l tiall'yV identical in so far' asthemold-cavities`v are`- concerned; Inl some cases; afl'at-face'moldy is dev sired, that is=l wherein* the parting 1ine-ris in` ai singleplane. This type of mold is-illustrated in Figs. 1, 3; and- 4': In other casesdt is` desirable to provide a so-called staggered. mold; that is; whereinA adjacent. strands.are offset. onopposite sides of. the`l controllplaneofithefgrid, and a mold2 producing.` grids on thistypeis, illustratednllligs.; 5to 8;.inclusive..y I

In theembodimentshown in Figs;.1\3..and4,. a portion of a mold section ,l1 isaillustratedand; comprisesI a moldA cavity-2. which' cavity includes a marginal casting.; groove: 3; horizontal rib; grooves 4, and intersecting vertical strand grooves 5. Terminalzlugcavities 6.-arealso provided.

Fig. 2- isa diagrammatic elevationu ofA av double grid produced by this typeof moldand-,showsthe. grid after it hasbeen. trimmed. The view. illustrates two integral grids 'I and 8V which. are cast in thev same mold and may. be separated after being` cast and trimmed to provide two. smaller. grids. The transversel ribgrooves il of' the mold are larger. than the strand grooves andare of" tionship for molding. In orderY to enable the moldsl to beu completely filled by molten metal,

compression chambers are provided'wherein the"` entrapped gases are just sufficientlyv compressed by' thek Weight of the molten metalA to enable the.

prf.

ns and without permitting the metal to ow into the compression chambers. In order to accomplish this, elongated grooves 9 are provided in each facet formed in the mold between the strand grooves 5 and the transverse reinforcing rib grooves 4. These compression grooves 9 are preferably provided in each mold section, as illustrated'A in Figs; 3 vand 4,` andare preferably substantially ofthe shape illustrated. Itwill be apparent, however, that the grooves may be of any convenient shape and in only one mold section if desired, the only requirement being that they should be of sufiicient size and so related to the strand grooves. as to enable a proper gas compression to provideA for completely filling the mold withoutins: Thezmold is provided with an inletv -opening |0"an'd.`with.gate grooves Il to facilitate line as shown' at I5"(Fig; 6)".. This 'is'accomplished by 'forming' each mold section by'milling or other wise. inthe direction of the: strands toV form4 the .corrugated parting line' and the strand' grooves;

I4,` complementary' grooves I4' being formed in" each mold section; Compression .chambers'in the' form of elongated grooves` l 6" are then' formedI one groove in each'l facet of thev rnoldl between'each pair of strands; angular` in cross, section', asA illustratedin- Fig'. 6,

as' this shape providesr for' convenient milling'V without undereutting;` The4 compression' grooves- I 6" arev preferably' in onlyfon'e section of the mold Howevenit will be' apparent that complementaryv grooves mayl be cut in both sections if desired;

the only'requirement being that they should be of'sucient size-and extent to allow Vfor the proper described;

The use of compression'. chambers instead of' sary to trim atA least'L the top and. bottom edges to remove. the sprueand 1 anyoutwardly extend*- ing fins which may haveformedorr the grid.y Thisl requires more or less handling of the grid, and. iti isdesirable. that a. reinforcing n be providedv on the bottom edge of` the grid' for that purpose.

In the embodimentflast described', the'cutterA which forms the corrugated parting'line inthe mold' continues the cut beyondthe bottom ofthe.

Igridcavity as vshown at IT. These' extended cor` rugations' terminate'in a marginal' slotflr,` which latter forms a horizontal reinforcing rib-on the n formed" by the extended'corrugations Il'. A. very light additional' cut is' taken on the terminal' corrugations l1' so that a veryl thin corrugated" finis formed as showninfFigs."Tandv v8*; and; as

thisv nn. terminatesin'l the'horizontal' channel f8;

mold C'Olnplellt"1`I1l without the' formation of* 75"this cliasnnel'forms a compression chamber which;

These chambers are preferablyA is not required to be completely filled with the molten metal. The' thin :corrugated iin forms `a sulciently rigid reinforcement so that'the` fin is not bent .when the grid drops from the mold.

Therefore, this 1in,` provides a rigid element for l as the `heavy border portion usually fills rst andv airis trapped in theycenter portions. This reinforcement is accomplished without any material waste of metal over the usual methods.

The two mold sections form what may aptly .be termed die plates, and these die plates are preferablyformed with complemental mold cavities. The compression grooves in either embodiment shown may be in only one die plate or, if desired, complemental grooves may be formed so that each pair of grooves forms a single compression chamber of suificient size and relationship to the adjacent casting grooves to perform the required function.

Fig. 9 is a face view of the upper portion of the drag die plate which co-operates with the complemental cope plate. The present invention is adapted for continuous .operation in suitable molding machines whereby, if desired, the molds may be continuously moved past a fixed lling station, at which station a predetermined amount of molten metal is dropped into the inlet orsprue opening In. Heretofore it has been found necessary to move the filling spout with the mold during the filling operation for the reason that, when the metal is dropped into themoldopening, the movement of the mold tends to cause the metal to overflow at the rear of the mold opening. With a mold construction such as illustrated in Fig. 9, theV mold may be filled during its continuous movement in the direction of the arrow, past a xed lling spout, without danger of overflow of the mold, while at the same time a substantially even distribution of the metal into the mold cavity is provided. This is accomplished by means of transverse baffles I9 which are formed by complemental ribs or partitions in the sprue openings of the die plates and with the sharp upper edges 20 of the baffles somewhat below the upper edge of the mold.

The transverse bailles I9 are somewhat widely spaced and distributed over the length of the mold opening in a manner to separate the incoming molten metal sufficiently to prevent overflow by the movement of the mold. The bailles terminate closelyadjacent the mold cavity, `but suiciently above the cavity to provide a passage 2| under each baffle to enable flow of the metal thereunder and provide auniform distribution of the metal to the mold cavity.` The advancing end of the mold cavity is preferably angularly inclined forwardly as shown at 22, While the rear Wall 23 is more nearly vertical to prevent overflow of any of the molten metal from the space between this end Wall and the adjacent baille I9.

As previously stated, terminal lug cavities B are provided in the complemental sections of the mold, and it is desirable that at least the outer portions of these'lugs be free of ns and that the edges be clean-cut and accurate so that the `lugs on the casting may be used forlocating the plug or movable mold section 24 `is slidably mounted in an opening 26 in the die-plate and is provided with rearwardly extending guide pins 21 slidably mounteduin complementary guide holes, thus preventing any rotary movement of the plug. 24` while 'permitting' axial movement thereof. Astop-bolt- 28 is .threaded into the plug 24 from the rear ofthe die plate, as illustrated, and a-spring29 tendsto'move the plug outwardly whenever thelmold isopen, the outward movement` being limitedby the head of the bolt 28. It willbe apparentthat, whenthemold is closed, the' outer surface of the plug will be -snugly pressed against the opposite die plate and the pressure of the spring'29 will cause the parting line around the edge of the grid lug cavity to be effectively sealed and an accurate clean-cut lug without ns will be formed on the grid.

It is intended, of course, that the invention' should not be limited to the specific embodiment or embodiments disclosed herein, since modifications may be made, and it is contemplated therefore, by the appended claims to cover any such modifications asfall within the true spirit and scope of this invention.

Having thus described this invention, what is claimed and desired to be secured by Letters Patent is:

1. In a grid mold of the character described, a die plate having a facet with a casting groove bounding said facet, said facet having a compression cavity therein, said compression cavity communicating only with the face of said facet.

from said casting grooves to form 'compression chambers when said mold is closed for casting.

4. A sectional grid mold having a central parting line and closely adjacent complementary strand casting grooves in said sections, said mold having air compression chambers communicating only with the parting line between said casting grooves and of a size and distribution to enable.

the-entrapped air to be compressed suciently therein during casting to permit the metal to completely ll said mold without flowing into said compression chambers.

' 5. In a grid casting mold, a die plate having a corrugated face, rib casting grooves extending transversely of said corrugations, a longitudinal strand casting groove in the top and bottom of each corrugation and forming with the adjacent rib grooves a facet inclined to the plane of said plate, and a compression groove in the inclined face of said facet remote from said casting grooves and communicating only with the face of said facet.

, 6. A grid mold comprising two Vcomplemental die plates, said plate-s having complemental corrugated faces forming a corrugated parting line, complemental transverse rib casting grooves in said corrugated faces, longitudinal strand casting grooves in the peaks and valleys of said corrugations to form inclined or substantiallyangular facets bounded by said casting grooves, and compression@A grooves im the inclined: faces of: saidlv facetsiand: communicating?onlw'wlibhz the partinglinezfaceslthereof;J v

'L1A grid: Inold comprising: diez platesi; having' vertically corrugated: complemented :facesiorming: a.2 corrugated? par-ting; linee. complemental strand'.` groovesfinthe peaks anjdivalleyslof said? corrugaftions;. and; transverse reinforcing" rib: grooves;. all oft said.E grooves.terminatingin'. ani enlargedfl marf-y ginal-oastinggroove; saidicorrugatons` exiendingfbeyonch the bottom;marginali castingf groove andi being.: slightly relievedz to l for-m' af veryfthirr corrfuA gatedxnzcavity:

sagaaugmm 82. Ai-vgnidi mold'v comprising; die platesz havingf. vertically corrugateduuomplement'al faces forming? 1' tions,:and transverse reinforcing?, ribgrooves, all.v

of; said;v grooves terminating; inl an: enlarged mars@ ginal. casting groovensaid corrugationsextending` beyond; the .bottom marginali-casting.' groove andl vbeing slightlyfrelieved tolform avery thinoorru-y l gatednlcavity; said yiin'eavity,L terminatingI ini` an y enlargedftransverse eolnpression`A groove.

HERBERT C'.' WINKEL. 

